Field
Embodiments of the present disclosure generally relate to a substrate support for use in a substrate processing chamber.
Description of the Related Art
Plasma enhanced chemical vapor deposition (PECVD) is generally employed to deposit thin films on substrates, such as organic light emitting diode (OLED) substrates and semiconductor substrates. PECVD is generally accomplished by introducing a precursor gas into a vacuum chamber having a substrate disposed on a substrate support. The precursor gas is typically directed through a gas distribution showerhead situated near the top of the vacuum chamber. The precursor gas in the vacuum chamber is excited into a plasma by applying an RF power to a chamber electrode from one or more RF sources coupled to the chamber. The plasma forms a layer of material on a surface of a substrate that is positioned on a substrate support. The gas distribution showerhead is generally connected to an RF power source and the substrate support is typically connected to the chamber body to create an RF power return path.
With large area substrates (i.e., substrates having a surface area of greater than about 1600 cm2), maintaining uniform conditions during processing can be challenging due to the enormous area in which the conditions need to remain controlled. It is oftentimes the case that one area of the substrate will be exposed to different processing conditions when compared to another area of the substrate. Additionally, when multiple substrates are processed on the same area as the large area substrate, each substrate may be exposed to different processing conditions.
Therefore, there is a need in the art for an apparatus that operates under substantially uniform processing conditions.